Electronic Theses and Dissertations Archive

Date

2026

Document Type

Dissertation

Degree Name

Doctor of Philosophy

Department

Biology

Committee Chair

Emily Puckett

Committee Member

Bernie Daigle

Committee Member

Cassandra Nuñez

Committee Member

Jennifer Mandel

Committee Member

Joseph Clark

Abstract

Genetics play a critical role in population resilience and vulnerability and are key to assessing conservation targets. Additionally, genetic patterns and individual genomes reveal insights into ecological interactions and evolutionary histories. My dissertation research uses these patterns to investigate the creation and loss of genetic variation, and to identify how these processes can be used to improve conservation outcomes for wildlife. This research first aimed to interpret contemporary signatures of genetic diversity within an evolutionary framework by linking demographic history to risk of inbreeding depression and genetic erosion across three species of bears: polar bears (Ursus maritimus), brown bears (U. arctos), and American black bears (U. americanus). (chapter 1). I found that incongruent trends between historical and contemporary genomic signatures can indicate genetic erosion within populations and may serve as a diagnostic for management intervention. This dovetailed into work disentangling adaptive and neutral evolutionary processes to interpret intraspecific genetic variation within the eastern lineage of American black bear (chapter 2). This context allowed for evaluation of the conservation and taxonomic status of U. a. luteolus—the Louisiana black bear— following their de-listing from the Endangered Species Act. My results were consistent with layered loss of diversity across populations rather than adaptive differentiation. While these data did not support the current taxonomic classification of the purported subspecies, they did indicate that genomic recovery lags behind demographic recovery and that ongoing management is warranted. Finally, in the service of regional genomic recovery of the Louisiana black bear, I investigated relationships between gene flow and movement, landscape structure, and the scale of landscape variation across the Lower Mississippi Alluvial Valley. While there was congruence between gene flow and previously identified daily movement behavior, habitat structure at a local level had the largest impact on genetic connectivity. These results suggest that habitat restoration intended to reduce isolation across this metapopulation should not target construction of narrow habitat corridors, but instead expand existing core habitat.

Comments

Data is provided by the student.

Library Comment

Dissertation or thesis originally submitted to ProQuest/Clarivate.

Notes

Open Access

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